JOURNAL OF CROP ECOPHYSIOLOGY (AGRICULTURE SCIENCE)
Year:2009 | Volume:3 | Issue:10|Papers Count:8

Cold damage to winter oilseed rape is caused by temperatures around 0ºC during early fall and spring and below 0ºC during winter. The study was conducted in factorial experiment with two factors, planting dates (Sept. 11 and Sept. 26) and six promising genotypes with three replications at Agricultural Research and Natural Resources Center of East Azarbaijan during 2003-4. The results indicated that the genotypes in second planting date produced lower number of leaves, crown diameter, dry weight, seed and oil yields. Correlations of seed and oil yields with leaf numbers per plant, crown diameter and plant dry weight were positive and significant, while they were negative with percent of cold damage. It seems that the leaf number, crown diameter and plant dry weight can be used for determining cold tolerant genotypes and suitable planting dates of winter oilseed rape when freezing  temperature prevails.

In order to study the effects of biofertilizers on seed yield and yield components of three sunflower cultivars a two-year research was carried out at Agricultural Research Station of Khoy during 2007-2008. A factorial experiment based on randomized complete block design with four replications was used. The cultivars of sunflower, as the first factor, were Hisun33, Alstar and Euroflor; and the second factor consisted of different combinations of biofertilizer inoculants and chemical fertilizers (50% K2SO4+biosulfur, 100% K2SO4+biosulfur, 100% K2SO4, 50% urea+azotobacter, 50% urea+nitroxin, 50% urea+azotobacter+nitroxin, 100% urea, 100% urea+100% K2SO4 ) in 8 levels. The results of the experiment showed that effects of cultivar and fertilizer on number of seed per head, 1000 seed weight, seed and oil yields were significant. The interaction effect also was significant on harvest index and oil yield. Mean comparison among cultivars showed that Hisun 33, produced higher yield and yield components (707 seed per head and 1000 seed weight of 56.7 grams, seed yield of 3832 and oil yield of 1705 kg per hectare respectively) than the other two cultivars. Among the different levels of fertilizers biosulfur+100% K2SO4 and 50 % urea+azotobacter+nitroxin had the highest positive effect on seed and oil yields increase. It can be concluded that use of biofertilizer reduces chemical fertilizer applications and improves both quantity and quality of oil in these cultivars.

In order to evaluate the reflection of sugar beet cv. Rasul to application methods of micro elements, a factorial experimental based on randomized complete blocks design with three replications was conducted during 2006. The treatments were types of micro elements at 5 levels: without the use of micro elements (control), ZnSo4, MnSo4, FeSo4 and Boric acid and the application methods at 3 levels: coated with the seed, soil application and foliar application. The foliar application treatments, with 0.005 concentrations experimental in per units were performed at two times, first in 8-10 and second in 14-16 leaf stages. The characteristics evaluated were: root yield, biomass, and harvest index, percentage of sugar and dry matter. ANOVA showed that the effect of micro elements on root yield, harvest index, percentage of dry matter and sugar were significant. The effect of the micro elements application method and interaction of examined factors was significant only in root yield and percentage of sugar. Based on the results obtained it can be said that increased in root yield, sugar percent and dry matter, harvest index and biomass significantly. Foliar application of Fe and Mn and the soil application of B and Zn produced higher root yield as compared with the other application methods. The high percentage of sugar production was made possible by the foliar application of Fe and soil application of other 3 elements. The highest root yield with Fe foliar application was equal to 6.143 kg.m-2 and the highest percentage of sugar with soil application of Zn was equal 18.32%, which resulted in the highest percentage of root dry matter production in (19.44%). The application of micro elements increased harvest index from the minimum amount 53.85% to maximum amount 72.27% when Mn was used. Thus, the application of micro elements, despite the methods used can increase percentage of sugar, by increasing leaf area duration, photosynthetic ability of plant and metabolic functions.

To evaluate morpho-physiological traits of 14 advance bread wheat lines and two local check varieties (Sardari and Azar-2) against drought and their relations to grain yield, an experiment was carried out in a RCBD with 3 replications under both rain fed and supplementary irrigation conditions at Maragheh Agricultural Research Station during growing season of 2008-9. To quantify drought response of genotypes, several indices such as SSI, TOL, MP, GMP and STI were applied. Analysis of variance showed that environment × genotype interaction and effect of genotypes were significant at 1% level of probability. Based on the results obtained under rain-fed condition, lines number 8 and 16 had 2080 and 2217 kg/ha respectively, while under supplementary irrigation line number 7 produced highest grain yield (3525 kg/ha). Results indicated that line number 16 had the highest GMP, MP and STI value whereas line number 12 had the lowest TOL value. Correlation analysis of grain yield with stress tolerance indices revealed that GMP, MP, STI had high positive correlation with grain yield in both conditions. It can be concluded that these indices are the most suitable measures to identify drought resistant lines.

To determine the efficiency of photosystem ΙΙ inheritance and its relationships with terminal drought tolerance in bread wheat, an experiment was carried out during 2006- 2008 at Ardebil Islamic Azad University. Heritability of traits was estimated by using an 8×8 diallel cross in greenhouse. To evaluate the relationships between traits, 18 wheat varieties were grown in RCBD with three replications, both under normal and terminal drought conditions, in the field. Chlorophyll flourescens parameters and drought tolerance indices were then mesured. Based on the results, it was found that in general, additive-dominance model was effective in determining inheritance of all of the parameters. Results also revealed that dominance effects are more important than additive effects. It was also found that all of the parameters are under control of overdominance and consequently had relatively low narrow sense heritability. However, the broad sense heritabilities of traits were very high. It was also observed that F0 and Fm had in general non-significant correlations with drought tolerance. However, Fv/Fm index showed relatively positive correlations with drought tolerance. Due to high broadsense heritabilities of traits, their significant correlations with drought tolerance, rapidity, less expensiveness and non destructivity of chlorophyll fluorescence measurement, it max be concluded that Fv/Fm index can be a complementary criterion for selection of drought tolerant genotypes.

To evaluate the effect of foliar application of Mn and Zn micronutrients on qualitative and quantitative characteristics of pearl millet under drought stress a field experiment was conducted in 2008. The experiment was conducted in split plot design with tree replications. Main plots were assigned different levels of drought stresses (S1=full irrigation, S2=withholding irrigation in vegetative growth stage, and S3=withholding irrigation in flowering stage). Sub plots were four levels of micronutrient foliar applications (F1=no foliar application, F2=3000 ppm foliar application of manganese sulfate, F3=3000 ppm foliar application of zinc sulfate, and F4=foliar application of manganese sulfate+zinc sulfate). Results indicated that the highest fresh forage (41073 kg/ha) and dry matter (9775 kg/ha) were obtained from S1F4 treatment. Furthermore, the highest ash (12.07%), crude protein (18.65%) and nitrogen (2.83%) achieved from this treatment (S1F4). Moreover the highest zinc (240.8 mg.g-1) and manganese (43.5 mg.g-1) content in millet forage also was obtained from treatment of full irrigation with separate foliar applications of these two elements. The most crude fiber and phosphorus content in millet forage obtained from full irrigation treatment. But, this treatment did not have significant effect on potassium, manganese and zinc content in forage. Meanwhile, foliar treatments didn' t have significant effect on crude fiber, potassium content in millet forage.

To increase yield of sunflower, it is essential to determine proper sowing dates for its cultivars. A factorial experiment was carried out with 2 factors in RCBD with 3 replications at the Agricultural and Natural Rresources Research Station of Khoy, Iran, during 2007-2008. Results showed that sowing date had significant effects on the plant height, stem diameter, percentage of empty achenes and harvest index. Latest planting date reduced all of the parameters under study (except empty achenes percentage). Delaying planting date reduced seed yield. The yield of Azar-gol, due to its greater head diameter, seed number per head and heavy seeds, was higher than the others. Highest seed yield was obtained from Azar-gol at second sowing date. Cultivars producing over 3000 kg seeds per hectare at latest sowing date in this regions, would be promising ones to be used in double cropping system and thus increase farmers income.

To evaluate the effect of different methods of fertilizers consumption of micro Jeta corn cultivar yield and growth analysis, testing in Tabriz in 2008 and based on a factorial randomized complete block design with three replications was conducted. Treatments were six type of micronutrients (control, ZnSO4 , MnSO4 , H3 BO3 , FeSO4 and complete micronutrients) and three methods of application (soil application, seed coating and foliar application).The results showed that the effect of different fertilizers and methods of various micro consumption in connection with performance traits, harvest index, plant dry weight and leaf area at 1% level was significant. ZnSO4 foliar application on the highest yield 16.04 tons and seed coating by FeSO4 equivalent of 11.85 tons per hectare was caused. Foliar application mixture fertilizer and ZnSO4 , respectively, the most effect on plant height and 1000 grain weight and increased 19 and 28 percent in control. The results showed that the seed coating by H3 BO3 consumption leads to production of maize was. Mixture foliar application fertilizers lead to production of plant dry weight equivalent to most be 335.6 g. Foliar application on the whole cause’s plant growth has been the most special leaf area. Mixed fertilizers foliar application 60 days after the most effect in increasing dry matter accumulation than the amount of time has had relative growth rate and leaf weight ratio has increased, so that expression can be used especially micro ZnSO4 fertilizers cause increase the quality and quantity of corn SEED PRODUCED.